# Copyright (c) 2012 - 2017, Lars Bilke
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
#    may be used to endorse or promote products derived from this software without
#    specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# CHANGES:
#
# 2012-01-31, Lars Bilke
# - Enable Code Coverage
#
# 2013-09-17, Joakim Söderberg
# - Added support for Clang.
# - Some additional usage instructions.
#
# 2016-02-03, Lars Bilke
# - Refactored functions to use named parameters
#
# 2017-06-02, Lars Bilke
# - Merged with modified version from github.com/ufz/ogs
#
#
# USAGE:
#
# 1. Copy this file into your cmake modules path.
#
# 2. Add the following line to your CMakeLists.txt:
#      include(CodeCoverage)
#
# 3. Append necessary compiler flags:
#      APPEND_COVERAGE_COMPILER_FLAGS()
#
# 4. If you need to exclude additional directories from the report, specify them
#    using the COVERAGE_EXCLUDES variable before calling SETUP_TARGET_FOR_COVERAGE.
#    Example:
#      set(COVERAGE_EXCLUDES 'dir1/*' 'dir2/*')
#
# 5. Use the functions described below to create a custom make target which
#    runs your test executable and produces a code coverage report.
#
# 6. Build a Debug build:
#      cmake -DCMAKE_BUILD_TYPE=Debug ..
#      make
#      make my_coverage_target
#

include(CMakeParseArguments)

# Check prereqs
find_program(GCOV_PATH gcov)
find_program(
  LCOV_PATH
  NAMES
    lcov
    lcov.bat
    lcov.exe
    lcov.perl
)
find_program(GENHTML_PATH NAMES genhtml genhtml.perl genhtml.bat)
find_program(GCOVR_PATH gcovr PATHS ${PROJECT_SOURCE_DIR}/scripts/test)
find_program(SIMPLE_PYTHON_EXECUTABLE python)

if(NOT GCOV_PATH)
  message(FATAL_ERROR "gcov not found! Aborting...")
endif() # NOT GCOV_PATH

if("${CMAKE_CXX_COMPILER_ID}" MATCHES "(Apple)?[Cc]lang")
  if("${CMAKE_CXX_COMPILER_VERSION}" VERSION_LESS 3)
    message(FATAL_ERROR "Clang version must be 3.0.0 or greater! Aborting...")
  endif()
elseif(NOT CMAKE_COMPILER_IS_GNUCXX)
  message(FATAL_ERROR "Compiler is not GNU gcc! Aborting...")
endif()

set(
  COVERAGE_COMPILER_FLAGS
  "-g -O0 --coverage -fprofile-arcs -ftest-coverage"
  CACHE INTERNAL ""
)

set(
  CMAKE_CXX_FLAGS_COVERAGE
  ${COVERAGE_COMPILER_FLAGS}
  CACHE STRING "Flags used by the C++ compiler during coverage builds." FORCE
)
set(
  CMAKE_C_FLAGS_COVERAGE
  ${COVERAGE_COMPILER_FLAGS}
  CACHE STRING "Flags used by the C compiler during coverage builds." FORCE
)
set(
  CMAKE_EXE_LINKER_FLAGS_COVERAGE
  ""
  CACHE STRING "Flags used for linking binaries during coverage builds." FORCE
)
set(
  CMAKE_SHARED_LINKER_FLAGS_COVERAGE
  ""
  CACHE
    STRING "Flags used by the shared libraries linker during coverage builds."
    FORCE
)
mark_as_advanced(
  CMAKE_CXX_FLAGS_COVERAGE
  CMAKE_C_FLAGS_COVERAGE
  CMAKE_EXE_LINKER_FLAGS_COVERAGE
  CMAKE_SHARED_LINKER_FLAGS_COVERAGE
)

if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
  message(
    WARNING
      "Code coverage results with an optimised (non-Debug) build may be misleading"
  )
endif() # NOT CMAKE_BUILD_TYPE STREQUAL "Debug"

if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
  link_libraries(gcov)
else()
  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --coverage")
endif()

# Defines a target for running and collection code coverage information Builds
# dependencies, runs the given executable and outputs reports. NOTE! The
# executable should always have a ZERO as exit code otherwise the coverage
# generation will not complete.
#
# SETUP_TARGET_FOR_COVERAGE( NAME testrunner_coverage                    # New
# target name EXECUTABLE testrunner -j ${PROCESSOR_COUNT} # Executable in
# PROJECT_BINARY_DIR DEPENDENCIES testrunner                     # Dependencies
# to build first )
function(SETUP_TARGET_FOR_COVERAGE)

  set(options NONE)
  set(oneValueArgs NAME)
  set(multiValueArgs EXECUTABLE EXECUTABLE_ARGS DEPENDENCIES)
  cmake_parse_arguments(
    Coverage
    "${options}"
    "${oneValueArgs}"
    "${multiValueArgs}"
    ${ARGN}
  )

  if(NOT LCOV_PATH)
    message(FATAL_ERROR "lcov not found! Aborting...")
  endif() # NOT LCOV_PATH

  if(NOT GENHTML_PATH)
    message(FATAL_ERROR "genhtml not found! Aborting...")
  endif() # NOT GENHTML_PATH

  # Setup target
  add_custom_target(
    ${Coverage_NAME}
    # Cleanup lcov
    COMMAND
      ${LCOV_PATH}
      --directory
      .
      --zerocounters
      # Create baseline to make sure untouched files show up in the report
    COMMAND
      ${LCOV_PATH}
      -c
      -i
      -d
      .
      -o
      ${Coverage_NAME}.base
      # Run tests
    COMMAND
      ${Coverage_EXECUTABLE}
      # Capturing lcov counters and generating report
    COMMAND
      ${LCOV_PATH}
      --directory
      .
      --capture
      --output-file
      ${Coverage_NAME}.info
      # add baseline counters
    COMMAND
      ${LCOV_PATH}
      -a
      ${Coverage_NAME}.base
      -a
      ${Coverage_NAME}.info
      --output-file
      ${Coverage_NAME}.total
    COMMAND
      ${LCOV_PATH}
      --remove
      ${Coverage_NAME}.total
      ${COVERAGE_EXCLUDES}
      --output-file
      ${PROJECT_BINARY_DIR}/${Coverage_NAME}.info.cleaned
    COMMAND
      ${GENHTML_PATH}
      -o
      ${Coverage_NAME}
      ${PROJECT_BINARY_DIR}/${Coverage_NAME}.info.cleaned
    COMMAND
      ${CMAKE_COMMAND}
      -E
      remove
      ${Coverage_NAME}.base
      ${Coverage_NAME}.info
      ${Coverage_NAME}.total
      ${PROJECT_BINARY_DIR}/${Coverage_NAME}.info.cleaned
    WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
    DEPENDS ${Coverage_DEPENDENCIES}
    COMMENT
      "Resetting code coverage counters to zero.\nProcessing code coverage counters and generating report."
  )

  # Show info where to find the report
  add_custom_command(
    TARGET ${Coverage_NAME} POST_BUILD
    COMMAND ;
    COMMENT
      "Open ./${Coverage_NAME}/index.html in your browser to view the coverage report."
  )

endfunction() # SETUP_TARGET_FOR_COVERAGE

# Defines a target for running and collection code coverage information Builds
# dependencies, runs the given executable and outputs reports. NOTE! The
# executable should always have a ZERO as exit code otherwise the coverage
# generation will not complete.
#
# SETUP_TARGET_FOR_COVERAGE_COBERTURA( NAME ctest_coverage                    #
# New target name EXECUTABLE ctest -j ${PROCESSOR_COUNT} # Executable in
# PROJECT_BINARY_DIR DEPENDENCIES executable_target         # Dependencies to
# build first )
function(SETUP_TARGET_FOR_COVERAGE_COBERTURA)

  set(options NONE)
  set(oneValueArgs NAME)
  set(multiValueArgs EXECUTABLE EXECUTABLE_ARGS DEPENDENCIES)
  cmake_parse_arguments(
    Coverage
    "${options}"
    "${oneValueArgs}"
    "${multiValueArgs}"
    ${ARGN}
  )

  if(NOT SIMPLE_PYTHON_EXECUTABLE)
    message(FATAL_ERROR "python not found! Aborting...")
  endif() # NOT SIMPLE_PYTHON_EXECUTABLE

  if(NOT GCOVR_PATH)
    message(FATAL_ERROR "gcovr not found! Aborting...")
  endif() # NOT GCOVR_PATH

  # Combine excludes to several -e arguments
  set(COBERTURA_EXCLUDES "")
  foreach(EXCLUDE ${COVERAGE_EXCLUDES})
    set(COBERTURA_EXCLUDES "-e ${EXCLUDE} ${COBERTURA_EXCLUDES}")
  endforeach()

  add_custom_target(
    ${Coverage_NAME}
    # Run tests
    ${Coverage_EXECUTABLE}
    # Running gcovr
    COMMAND
      ${GCOVR_PATH}
      -x
      -r
      ${PROJECT_SOURCE_DIR}
      ${COBERTURA_EXCLUDES}
      -o
      ${Coverage_NAME}.xml
    WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
    DEPENDS ${Coverage_DEPENDENCIES}
    COMMENT "Running gcovr to produce Cobertura code coverage report."
  )

  # Show info where to find the report
  add_custom_command(
    TARGET ${Coverage_NAME} POST_BUILD
    COMMAND ;
    COMMENT "Cobertura code coverage report saved in ${Coverage_NAME}.xml."
  )

endfunction() # SETUP_TARGET_FOR_COVERAGE_COBERTURA

function(APPEND_COVERAGE_COMPILER_FLAGS)
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${COVERAGE_COMPILER_FLAGS}" PARENT_SCOPE)
  set(
    CMAKE_CXX_FLAGS
    "${CMAKE_CXX_FLAGS} ${COVERAGE_COMPILER_FLAGS}"
    PARENT_SCOPE
  )
  message(
    STATUS "Appending code coverage compiler flags: ${COVERAGE_COMPILER_FLAGS}"
  )
endfunction() # APPEND_COVERAGE_COMPILER_FLAGS
